说明：  C语言写的简易的文件加密/解密工具，将文件加密为sec文件，经测试加密后无法被其他程序识别。解密时可原封不动地变回原来的文件（经测试，图片、视频加密后解密均能打开和播放）。使用时（显示：Error, file can not be found的时候）输入一个质数密码：223092871（2到23所有质数相乘加一，不易被破解），按回车后就能开启加密/解密功能。显示What would you do?(1/2)时，1为加密整个文件夹的文件，2为解密整个文件夹的文件 务必注意：生成的exe文件名称必须为enc.exe，以避免解密时解密自己而造成无法解密
(C language to write a simple file encryption/decryption tool, the file is encrypted as sec file, can not be recognized by other programs. Decryption can be intact to change back to the original file (after testing, pictures, video encryption can be decrypted to open and play). When using (display: Error, file can not be found) Enter a prime number Password: 223092871 (2 to 23 all prime multiplication plus one, not easy to be cracked), press Enter to turn on encryption/decryption function. Show what would you do? (1/2), 1 for encrypting the entire folder of the file, 2 for decrypting the entire folder of the file Be sure to note that the generated exe file name must be enc.exe to avoid decrypting itself while decrypting itself)